A bearing is a mechanical element that can fix a shaft at a certain position and rotate the shaft while supporting the shaft.
Bearings may be classified into a sliding bearing and a rolling bearing according to their contact state. The bearings may include an air foil bearing and the like. The air foil bearing is lubricated using an ambient air without use of lubricating oil from the motor. The air foil bearing including a top foil which is spaced apart from the shaft and a bump foil which is disposed on the outer circumference of the top foil. The air foil bearing may convert an air flow between the top foil and the shaft in the pressure and perform a lubricating function.
A rolling bearing may support a rotating shaft and include a rolling member such as a ball, roller, or needle which rotates together with an inner rim of the rolling bearing. The rolling bearing has a high reliability in its high-speed rotation. The rolling bearing can be used in a motor such as an electric motor, compressor, a generator, a transmission, or the like, which may include a rotating shaft that can rotate at a high speed.
When a rolling bearing is mounted in a motor, the rolling bearing may be supported by a motor body forming an external appearance of the motor, or may be supported by a bracket separately installed in the motor body. The weight of a rotating shaft may be transferred to the motor body or the bracket through the rolling bearing.
In some examples, the motor having the rolling bearing mounted therein may include an assembly of a plurality of parts and have an assembly tolerance. The rolling bearing provided in the motor and disposed in the motor housing can be distorted due to the assembly tolerance. In this case, the amount of abrasion of the rolling bearing may increase, and the lifespan of the rolling bearing may be shortened.